| 翻訳と辞書 |
| Cacao swollen-shoot virus ： ウィキペディア英語版 |
Cacao swollen-shoot virus
Cacao swollen-shoot virus (CSSV) is a plant pathogenic virus of the family Caulimoviridae that primarily infects cacao trees. It decreases cacao yield within the first year of infection, and usually kills the tree within a few years. Symptoms vary by strain, but leaf discoloration, stem/root swelling, and die-back generally occur. The virus is transmitted from tree to tree by mealybug vectors. It was first discovered in Ghana in 1936, and is currently endemic in Togo, Ghana and Nigeria.〔Dzahini-Obiatey, H., O. Domfeh, and F. M. Amoah. 2010. Over seventy years of a viral disease of cocoa in Ghana: From researchers' perspective. Afr. J. Agric. Res. 5:476-485.〕 Over 200 million trees have already been claimed by this disease, which has prompted Ghana to launch the most ambitious and costly eradication effort of any country in the world against a viral plant disease.〔
==Hosts and symptoms==
Cacao swollen-shoot virus (CSSV) principally infects ''Theobroma cacao'' (cacao tree) and has a major effect on crop yields. Within one year of infection yields decrease by 25%, and within two years by 50%. The trees are usually killed within 3 to 4 years.〔Crowdy, S. H., and A. F. Posnette. 1947. Virus diseases of cacao in West Africa. II Cross-immunity experiments with viruses 1A, 1B, 1C. Ann. Appl. Biol. 34:403-411.〕 Symptoms vary depending on the strain of virus. Main symptoms include: leaf chlorosis (interveinal), root necrosis, red vein banding in young leaves, small mottled pods, and stem/root swelling followed by die-back.〔Dongo, L. N., and S. B. Orisajo. 2007. Status of cocoa swollen shoot virus disease in Nigeria. Afr. J. Biotechnol. 6:2054-2061.〕 CSSV has also been isolated from alternative hosts ''Cola chlamydanta'', ''Ceiba pentandra'', ''Adansonia digitata'', ''Cola gigantean'' and ''Sterculia tragacantha''.〔 These alternate hosts display the same symptoms as infected cacao trees, but with less severity.〔Legg, J., and J. Bonney. 1967. Host Range and Vector Species of Viruses from Cola Chlamydantha K Schum Adansonia Digitata L and Theobroma Cacao L. Ann. Appl. Biol. 60:399-403.〕 Symptoms also vary with environmental conditions. Neither nutrition nor temperature changes have a perceivable effect on symptoms, but increased light intensity inhibits the development of root/stem swellings in infected plants.〔Asomaning, E. J. A., and R. G. Lockard. 1964. Studies on the physiology of cocoa (Theobroma cacao L.). I Suppression of swollen-shoot virus symptoms by light. Ann. Appl. Biol. 54: 193-198.〕 Shaded cacao trees exhibit decreased growth and slightly more severe symptoms.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Cacao swollen-shoot virus」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|